Merge commit '3554c527954441fd924586a49c7d99a89101ac7e' into glitch-soc/merge-upstream

Conflicts:
- `app/controllers/authorize_interactions_controller.rb`:
  Small conflict due to our theming system.
- `streaming/index.js`:
  Upstream refactored part of the streaming server.
  We had some extra logic for handling local-only posts.
  Applied the refactor.

app/models/instance.rb

@@ -21,6 +21,7 @@ class Instance < ApplicationRecord
     belongs_to :unavailable_domain # skipcq: RB-RL1031
   end
 
+  scope :searchable, -> { where.not(domain: DomainBlock.select(:domain)) }
   scope :matches_domain, ->(value) { where(arel_table[:domain].matches("%#{value}%")) }
   scope :by_domain_and_subdomains, ->(domain) { where("reverse('.' || domain) LIKE reverse(?)", "%.#{domain}") }